<?php
/**
 * This file is part of PHP_Depend.
 *
 * PHP Version 5
 *
 * Copyright (c) 2008-2011, Manuel Pichler <mapi@pdepend.org>.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *
 *   * Neither the name of Manuel Pichler nor the names of his
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * @category   QualityAssurance
 * @package    PHP_Depend
 * @subpackage Code
 * @author     Manuel Pichler <mapi@pdepend.org>
 * @copyright  2008-2011 Manuel Pichler. All rights reserved.
 * @license    http://www.opensource.org/licenses/bsd-license.php  BSD License
 * @version    SVN: $Id: Collection.php 1030 2010-01-01 12:06:13Z mapi $
 * @link       http://pdepend.org/
 */

/**
 * Static composite filter for code nodes. This class is used for an overall
 * filtering.
 *
 * @category   QualityAssurance
 * @package    PHP_Depend
 * @subpackage Code
 * @author     Manuel Pichler <mapi@pdepend.org>
 * @copyright  2008-2011 Manuel Pichler. All rights reserved.
 * @license    http://www.opensource.org/licenses/bsd-license.php  BSD License
 * @version    Release: 0.10.7
 * @link       http://pdepend.org/
 */
final class PHP_Depend_Code_Filter_Collection implements PHP_Depend_Code_FilterI
{
    /**
     * Singleton instance of this filter.
     *
     * @var PHP_Depend_Code_Filter_Collection $_instance
     */
    private static $_instance = null;

    /**
     * Singleton method for this filter class.
     *
     * @return PHP_Depend_Code_Filter_Collection
     */
    public static function getInstance()
    {
        if (self::$_instance === null) {
            self::$_instance = new PHP_Depend_Code_Filter_Collection();
        }
        return self::$_instance;
    }

    /**
     * Constructs a new static filter.
     */
    private function __construct()
    {
    }

    /**
     * An optional configured filter instance.
     *
     * @var PHP_Depend_Code_FilterI
     */
    private $_filter = null;

    /**
     * Sets the used filter instance.
     *
     * @param PHP_Depend_Code_FilterI $filter The new filter instance.
     *
     * @return void
     * @since 0.9.12
     */
    public function setFilter(PHP_Depend_Code_FilterI $filter = null)
    {
        $this->_filter = $filter;
    }

    /**
     * Returns <b>true</b> if the given node should be part of the node iterator,
     * otherwise this method will return <b>false</b>.
     *
     * @param PHP_Depend_Code_NodeI $node The context node instance.
     *
     * @return boolean
     */
    public function accept(PHP_Depend_Code_NodeI $node)
    {
        if ($this->_filter === null) {
            return true;
        }
        return $this->_filter->accept($node);
    }
}
